Microstructure and Properties of CrAlSiN Coatings Deposited by HiPIMS and Direct-Current Magnetron Sputtering

Qixiang Fan,Tiegang Wang,Zhenghuan Wu,Yanmei Liu,Yangmengtian Liang

doi:10.3390/coatings9080512

Qixiang Fan, Tiegang Wang + Show 3 more

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https://doi.org/10.3390/coatings9080512

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Journal: Coatings	Publication Date: Aug 13, 2019
Citations: 11	License type: CC BY 4.0

Affiliation: Tianjin University of Technology and Education

Abstract

Four CrAlSiN coatings with different Al contents were prepared by varying Al sputtering power using a combined method of high power impulse magnetron sputtering (HiPIMS) and direct current magnetron sputtering (DCMS). Microstructure, chemical compositions and mechanical properties of the four coatings were characterized by XRD, XPS, SEM, TEM, nano-indentation etc. Results showed that the four coatings possessed face-centered cubic (fcc) CrN phase with Al and part of Si dissolved in it. Another part of Si existed as amorphous phase in the coatings. All the four coatings had columnar structure and formed in epitaxy growth by template effect. With increasing Al sputtering power, the Al content increased from 11.4 to 17.6 at.% gradually, while the Cr content decreased a little. The hardness of the CrAlSiN coatings increased initially probably due to the refinement of the coating grain size, while it decreased afterwards mainly caused by the aggregation of small particles leading to rougher surface and defects formed in the coatings. The elastic modulus and adhesive strength possessed the same variation tendency as the hardness versus Al sputtering power. The CrAlSiN coating with Al sputtering power of about 0.8 kW had the highest hardness of about 26.7 GPa and adhesive strength of about 27.2 N.

Highlights

Binary coatings like CrN, TiN have been applied in industries such as molding dies, wear components and cutting tools for the past decades, due to their high hardness and good wear resistance [1,2,3]
The hardness of the CrAlSiN coatings increased initially probably due to the refinement of the coating grain size, while it decreased afterwards mainly caused by the aggregation of small particles leading to rougher surface and defects formed in the coatings
As the Al sputtering power increased from 0.6 to 1.2 kW, the Al content in the four CrAlSiN coatings increased from 11.4 to 17.6 at.% gradually, which was attributed to the fact that more Al atoms could be sputtered out, transported to and deposited on the substrate at higher sputtering power

Summary

Introduction

Binary coatings like CrN, TiN have been applied in industries such as molding dies, wear components and cutting tools for the past decades, due to their high hardness and good wear resistance [1,2,3]. Research shows that multicomponent coating e.g., CrAlSiN, TiAlSiN and CrAlSiWN possesses good mechanical properties, oxidation resistance and cutting properties [4,5,6]. It is reported to possess super hardness attributing to two aspects: on one hand, the element Al could be dissolved in CrN lattice space substituting for the Cr sites and plays as a barrier to dislocation propagation [7]; on the other hand, Si tends to segregate along the grain boundaries as amorphous Six Ny leading to grain boundary hardening and crystal size refinement since it could hinder the growth of the fcc-(Cr,Al)N phase [8].

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